<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* ol li{
            color: red;
        } */
         .mm li{
            color: blue;
         }
    </style>
</head>
<body>
    <ul>
        <li>hello</li>
    </ul>
    <ol class="mm">
        <li>world</li>
    </ol>
</body>
</html>